"The scum factor, who knows who's done it, only care for themselves. So now there's an interest for someone to make a gain, [the killer] will be very scared," the 54-year-old told the Herald today.
Blackmoore, a 21-year-old mum who was 10 weeks' pregnant, was stabbed 39 times in her house on Vancouver Cres in the Christchurch suburb of Wainoni on the blustery, warm Thursday evening of August 17, 1995.
Her 2-year-old son Dillon was sleeping in his bedroom at the time of her death.
Her partner, Anderson discovered her body when he returned home after work at 11.20pm that night.
Time has done little to ease Anderson's pain and suffering at losing the woman he loved.
"It's virtually the same as when it happened," he said.
"It's still raw, you just learn to live with it. It's like a disability – say you lost your arm – you learn to live with your loss."
Investigations manager Detective Inspector Corrie Parnell said it was a "horrific" crime which took the life of a young mother "with her whole life ahead of her".
"Since Angela's murder our focus has been on bringing the person responsible to justice, and although many years have passed that focus has not changed," Parnell said.
"With the passing of time allegiances may have changed and we're appealing to anyone with information that might help, no matter how small or seemingly insignificant, to contact us."
Since the $100,000 reward – the largest ever offered by New Zealand police - was launched this morning, police have already received four phone calls from the public.
The cash would only be paid out if the tip-off led to the murderer being, firstly identified, and then convicted in a court of law.
The file has been reviewed several times over the past two decades.
More than 100 people have been spoken to during the course of the investigations.
However, there's never been enough evidence to lay charges.
Today there are fewer than 10 persons of interest remaining who haven't been ruled out, Parnell says.
While 24 years have passed, Parnell believes the killer's "cognitive load of burden" will not have passed.
"I encourage them to come forward, and secondly, anybody that may have been of assistance in the crime, or has material information or was close to those persons involved, that same burden will be present, and I encourage them to come forward," Parnell said.
Fingerprints were taken from the house and remain unidentified. They have been kept on the police national DNA database, along with other items taken from the scene, and are regularly checked as advances in DNA testing keeps getting better.
Parnell said you live in hope of one day getting a call from forensic experts who have nailed a trace match.
Anyone with any information about the case can call a dedicated police phone number, 0800 22 1995.